Plastic lamp shade with circulating air passage



y 1951 H. A. SNIDER 2,554,647

PLAS TIC LAMP SHADE WITH CIRCULATING- AIR PASSAGE Filed June 8, 1948FIE-J 15 l VENTOR.

Hermon 4 mqer I l M ATTORNEY Patented May 29, 1951 PLASTIC LAMP SHADEWITH CIRCULATING AIR PASSAGE Herman A. Snider, Newton, Mass.

Application June 8, 1948, Serial No. 31,622

7 Claims.

The present invention relates to a translucent lamp shade which, in thepresent invention, is constructed of thermo-plastic material, preferablypolyamids such as synthetic linear condensation products of diamines anddicarboxylic acids with or without coloring agents, dyes and stabilizerssuch as nylon, which may be molded and which will withstand fairly hightemperatures without change of its character such as discoloration,warping and loss of light transmission eificiency.

In the lamp shade of the type of the present invention which appliesspecifically to indirect lighting fixtures as floor lamps, desk lamps orthe like, glass shades have been commonly used. These shades becomequite hot in the vicinity of the lamps themselves so that the shadesmust be made of material adapted to withstand high heat. In lamps ofthis type where indirect lighting is used it is also common to use 300watt lamps developing bulb temperatures of 385 F. to make up for thelight loss which is incurred by reflections from wall surfaces which.are for the most part'inefilcient light reflecting surfaces. Since inlamps of this type the shades are open at the top and the bottom restson and is enclosed in part by a metallic base, there'is little provisionfor conducting the heat away from the interior of the bowl or shade andthis too adds to the increase of the temperature of the shade in thevicinity of the lamps themselves.

Thermo-plastic materials, particularly the non-setting thermo-plasticswill either melt, warp, become cloudy, char or change theircharacteristics if too high a temperature is applied for any length oftime to them. Some thermoplastics break down at comparatively lowtemperatures, 150 to 250 F., as, for instance, cellulose acetate. Otherswill withstand higher temperatures in the neighborhood of 200 to 300? F.without bein materially afiected by the heat, but in most casescontinuous application of the higher temperatures will affect thethermo-plastics in such a way that they will finally become useless asmaterials for lamp shades of the present type used in this construction.a

In the present invention this difiiculty has been over-come by theconstruction of a lamp shade of thermo-plastic materials in which theheat is efiectively kept away from the thermo-plastic material such thatthe temperature of the material does not rise above its safe normalvalue which it can continually withstand for any number of hours. Notonly is the direct heat, kept away from the thermo-plastic materialv ofthe shade to .a great degree but also a continuous circulation of air isestablished uniformly over the region of highest temperature so that theshade is kept at a safe operating value.

This is accomplished in the present invention not only without in anyway interfering with efficient transmission of light, but in fact, byuse of means which provide a greater efficiency than would otherwisenormally be obtained in other: systems.

The shade in the present invention is a singleunit and is put on thelamp or removed as a, single unit since the air circulation and theother properties .are all provided as inherent elements of the unititself. The shade of the present invention as used for indirect lightingmay be applied to an enclosed base or to an open base with the sameeffect. The only requisite is that the lamp base to which the shade isto be applied has a rim of proper size opening and depth to accommodatethe shade.

The present invention will be described in the specification set forthbelow with reference to an embodiment as illustrated by the drawings inwhich Figure 1 shows an elevation of a shade and stand constructedaccording to the present invention with parts shown in fragmentarysection.

Figure 2 shows a fragmentary plan view of the shade looking upwards atthe throat end of the shade in the position shown in Figure 1.

Figure 3 shows a vertical section through the lower portion of the shadeand stand.

Figure 4 shows an enlarged detail section taken on the line 4-4 ofFigure 2 but including also a section through the stand.

Figure 5 shows an enlarged detail section taken on a line 5-5 of Figure2 but including also a section through the stand.

In the arrangement indicated in the drawings the lamp shade l ispreferably of the bowl type with a flared out horn or frustum of a conewith a throat aperture in the region of which it rests upon a suitablestand 2, which holds the electrical lamp for furnishing the light. Thestand 2is provided at its end with a flared out section 2| to receivethe base 4 of the shade, the 'wall of the section being spaced apartfrom the wall of the shade. This base 4 is provided with fluting 5 whichextends upwards beyond the line where the rim 6 of the flared outsection 2| of the base rests so as to provide spaces between the wall ofthe shade and the wall 20 of the flared out, section 2| except where theconvex projec tion of the fluting of the shade rests on the flared rimof the section 2|.

The shade itself is molded by injection or compression molding of athermo-plastic or thermosetting material which is translucent to adesired degree sumcient to give a general diffusion of light through theshade of a substantially lower intensity than that obtained through theindirect lighting. Such polyamides as nylon or other thermo-plasticresin which will withstand fairly high temperatures of the vicinity of200 F. without material deterioration or changes are suitable for thispurpose. The shade itself may be of the shape as shown in Figure 1 withsuccessive scallop section parallel to the wide edge down as far as thethroat portion of the shade. In this section, from the open throat endto the bowl section of the shade, the shade should have fluting in thedirection of its axis in its wall. These flutings such as shown at 5,Figure 2, alternate with projecting and recessed sections such as shownat l, and provide thereby a uniformly waving contour about the base ofthe shade. The inside of the shade in the throat section is lined with ametallic foil 8, of a smooth unwaved contour, fitting into the flaredout throat from the edge 9 in the vicinity of the throat opening to theedge I!) substantially at the end of the fluted section of the shade.The foil 8 touches the shade in the region of its inwardly projectedfluted surfaces such as H, and forms an air space for an upward airdraft between the foil and the material of the shade at the outwardlyprojecting wall sections as indicated at 12. The foil 8 may be providedwith a bright reflecting surface on both of its faces for the betterradiation of the heat. Air circulation is also obtained on the outerside of the shade base over the sections 7 where the shade on the insideis in contact with the foil 8. On the outside a space is providedbetween the wall 29 and the concave or inwardly projecting region it ofthe fluting through which upward circulation is established between theshade and the metallic wall of the stand, the hot air flowing outthrough the top rim, as' indicated by the arrow it. In the arrangement,therefore, shown in the application, a complete air circulation ismaintained in close proximity to both the inner and outer face of theshade at its base where the temperature is the hot' test. This isindicated more clearly in Figures 4' and 5. In Figure 4, the arrows l5|5show the travel of air on the inside of the wall and the outside of theconcave fluting at l. The contact formed by the fluted ridges 5 with theinside of the stand wall 2% provides 011 both sides of the ridges a thinpassage for air bordered by the outside wall of the shade.

In Figure 5 the path of circulation is shown on the inside of the shadebetween the foil 8 and the wall t of the shade. These elements borderthe space 12 through which air circulates as indicated by the arrows It.This circulation is on the inside of the shade and the use of the closespacing of the foil provides a means for confining the circulatory airclose to the surface of the shade itself. This is also true of thecirculation to the outside wall of the shade.

It will be noted from Figure 2 that the successive convolutions close toone another provide air cooling over a large shade surface quiteuniformly on both faces so that an efficient cool ing of the shade iseffectively accomplished. An additional feature obtained in thearrangement described is that the foil surface has an-efii- 4 cientreflector for the light which would otherwise be lost in the metal standitself. This light would simply go to heat up the metal stand at the topwhereas in the present arrangement a percentage of this light isreflected outward for its proper use. The reflecting surface is alsosuch as to prevent radiation to the base of the shade from the lightsource and yet it is eifectivel'y concealed so as not to interfere withthe general glow through the shade itself.

It will be noted that the foil is recessed slightly in the Wall of theshade so that its surface is continuous with the inner surface of theshade. Various types of foil may be used for the purpose, such asaluminum, or some alloy metal which: will retain a fairly bright innersurface for efiicient reflecting purposes.

It will further be noted that when the lamp shade is made of athermo-plastic material as set forth above, the particularly soft andpleasant light eifect is obtained through the material of the shade.This is due to the action of the plastic material in particular to thelarge molecular structure which causes a uniform dispersion of lightwith high surface reflective properties and low absorption. In addition,the plastic material of the type used for the present invention is notreadily fractured and will not shatter, break, oi crack if dropped,thereby greatly increasing its utility and light.

Having now described my invention, I claim:

1. In combination with an indirect lighting electric lamp fixture havingan open ended housing for the reception of a lamp shade surrounding thelamps, a lamp shade of a molded thermoplastic material having apartially translucent wall with a large top opening to permit indirectlighting and a bottom throat portion having' a comparatively smallersection adapted to fit into the open ended housing, the contour of saidthroat portion being shaped with respect to the open ended housing andspaced from the housing to provide air passages between the housing andthe throat portion spaced around 7 the outer surface of the throatportion where the shade is supported in said housing and a tom,said'thfoat section having its walls fluted in" a top-aridbottomdirection and a light refleeting metallic foil on the inside of thethroat section of the'wall touching the wall in the inwardlyproj'ecting" fluted regions and coextensive therewithform-ing a-irpassages in an'up and down direction adiaeent the inner surface of thethroat section of the lamp shade.

3.- In a combination of the type described, a lampshade ofthermo-plastic material having a large open bowl end at the top and asmall s'yfnmetrically positioned throat section at the bottom, saidthreat section having its walls fluted in the axial directions of theshade and a light r'eflectingmetallic r011 extending around the innersurface of the throat section spaced from the outwardly projectingfluted'regions forming a'ir passagesaxially of-the throat along theinner surfaces thereof am a comtinau'om of the type described', a lampshade of thermoplastic material having-a;

partially translucent wall with an open bowl type section and a throatportion axially symmetrical with the bowl and having a tapering flutedwall decreasing from the bowl end to the throat opening, a lightreflecting metallic foil lining the inside of said throat but spacedaway from the wall in the region of the fiutings forming a series of airpassages between the foil and the Wall extending generally in said axialdirection.

5. In a combination of the type described, a lamp shade of thermoplasticmaterial having a partially translucent wall with an open bowl typesection and a throat portion axially symmetrical with the bowl andhaving a tapering fluted wall decreasing from the bowl end to the throatopening, a light reflecting metallic foil lining the inside of saidthroat but spaced away from the wall in the region of the flutingsforming a series of air passages between the foil and the wall, saidfoil being set within the wall to form a continuous surface therewithextending generally in said axial direction.

6. In combination with an indirect lighting electric lamp fixture havingan open ended housing for the reception of a lamp shade surrounding thelamps, a lamp shade of a molded thermoplastic material having apartially translucent wall with a large bowl-like top opening to permitindirect lighting and a bottom throat portion having a comparativelysmaller section at its junction at the bottom of the bowl and taperingto a smaller end opening said throat portion adapted to fit into theopen ended housing, the contour of said throat portion being shaped withrespect to the open ended housing and spaced therefrom to provide airpassages between the housing and the throat portion spaced around theouter surface of the throat portion where the shade is supported in saidhousing and a refleeting metallic foil attached to the inner side of thethroat section of said shade spaced away from the inner surface of saidthroat section, to provide air passages between the foil and the throatsection of the shade, said metallic foil extending upwards notsubstantially further than the periphery of the housing wall.

7. In combination with an indirect lighting electric lamp fixture havingan open ended housing for the reception of a lamp shade of a mouldedthermoplastic material having a par tially translucent wall with a largebowl-like top opening to permit indirect lighting and a bottom throatportion having a comparatively smaller section adapted to fit into theopen ended housing, the throat portion being fluted in a top and bottomdirection and providing up and down air passages between the housingwall and the throat portion or the shade at intervals about the entirethroat portion of the shade, and a reflecting metallic foil lining theinside of the throat portion of the shade touching the Wall in theregion of the inwardly projecting flutings but otherwise spaced awayfrom said wall thereby forming air passages at the walls in the outerprojecting fluted regions of the throat of the shade.

HERMAN A. SNIDER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,267,749 DOlier May 28, 19181,777,824 Blitzer Oct. 7, 1930 1,824,047 Goldfinger Sept. 22, 19311,950,131 Barlow et a1 Mar. 6, 1934 1,980,183 Brosilow et a1. Nov. 13,1934 2,007,489 Westberg July 9, 1935 2,057,263 Perlmutter Oct. 13, 1936

